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1979 coils

How are you measuring secondary? Measure plug wire hole to plug wire hole, they do not ground externally per se---waste spark system....................
 
I measured it by setting meter to 20K , put one lead to one of the primary wires, and the other lead to the spark plug cap. Then I did the same to the end of the spark plug wire, to remove the cap from the equation, then straight into the coil with the spark plug wire removed. All came back no reading.

What does amc49 mean by "..plug wire hole to plug wire hole"?
 
'straight into the coil with the spark plug wire removed' is 'plug wire hole'.

Measuring all wrong there. BOTH the primary and secondary are inside the coil itself. Primary you measure one coil small wire to the other (coil + to coil -).

For secondary you measure one plug hole to the other of the same coil. On waste spark the secondary does not wire into the primary to have a common ground at all like a normal say car coil. Instead, it is wired between the two plug towers of the coil. Since one plug wire leads to the other, one plug out of each pair fires BACKWARDS, you got that right, one fires from center to electrode and the other of the pair fires the opposite direction, electrode to center. To the plugs the power jolt appears to be ac, it simply runs from the secondary down through one plug like normal and then ground through head to run back up the other plug backwards and back to secondary to complete the loop. Why problems with waste spark can often fail two plugs rather than one only, each plug relies on the other working right to complete the power circuit there.

Measuring one primary wire to anything coming out of the plug wire hole BETTER not get a reading, that would be a direct coil short.
 
oh man, am I testing wrong:( Will try amc49 way tomorrow and get back. Hoping its the coils though at this point- Have great compression, and spraying carb cleaner direct into engine no change and carbs have been extensively cleaned/ synced in recent past. Spark tested grounded to engine case has been inconsistent. Will let ya'll know.
 
They ALL say they have great compression....................spec is 170 psi. A real sore spot on these as nobody ever sets the valves. That not done any carb or ignition work is commonly wasted.
 
ok, I think Ive found something. Measured how amc49 describes, my L primary is 2.6, and R primary is 2.9. L secondary from hole to hole- no wire or cap- is 11.35k; with wire and caps is 16.5k. R secondary hole to hole- no wires or caps- 11.6k; with wires and caps 17.2k.

but what is interesting is that through a process of ellimination, one of the straight caps couldn't get a reading at all, but the wire would get a reading without that cap on. Am I safe to assume that cap is no good?
 
Could be a bad cap. You look for no more than 5K ohms in wire and cap and plug together. Once you have resistor in wire or cap then you DON'T want it at plug. One place only, some not watching end up with it in 3 places, or wire, cap and plug. I personally run zero resistance by choice and make up for it by slightly increasing plug gap which does the same thing but better there as it makes a bigger spark. The ignitions on these are fairly weak and need all the help they can get, resistance helps increase spark a little bit but too much is bad.

What valve clearance spec? The OEM service manual is flawed there, needs closer to .005" than the .003" they call for. The .003" allows for a -.001" tolerance down to .002" and for sure that will get you burned valves, BTDT. The cam journal holes are so big (up to .008" new) they allow the cams to shove around in varying amounts in the holes to alter your real world valve clearance, what you get with careful measuring is NOT real with engine in a running state. Why you throw the extra .002" in there for good measure, it solidifies your measurements to be solid. A .002" is essentially a real world .000" there, and one burned valve coming up.

Think I'm pulling your leg? Measure as careful as you can and roll the engine around to the EXACT same place and try to measure that same point again, half the time the number will NOT be the same. You will get variance enough to drive you crazy if you check it say five times.
 
Probably. There are no published figures, the service manual instead performs a spark gap distance test. Need at least 6.4 mm. spark there.
 
I'm now officially pulling out my hair. Went to buy new spark plug cap and had parts guy check old one to confirm it's bad and low and behold it gets a reading. All the caps were between 4.6k and 5.2k ohms. I'm assuming that's ok or do they have to be exactly 5k ohm?

Let's go back to beginning. Last week bike ran well coming out of winter storage. Bit hard to start but expected with old gas. Then it's issue with inconsistency dropping cylinders starts. Sometimes 1 dead cylinder or 2 and not always same ones. Now turns over but won't start at all.

Looked extensively into spark and seems ok when grounding to cylinder- at least no worse than when it was running. Compression is 135-150 psi and spraying carb cleaner into intake has no effect. Fuel was replaced with brand new including float bowls. Plugs get some wet gas on them when pulled so fuel going into cylinder.

Why won't it start? I'm baffled. Took pulse generator plate off everything tight so gap shouldnt have changed. Suppose I'll recheck valves. Where do I go from here? Argg
 
The 5K on each cylinder resistance by no means has to be exact, simply a target to shoot for. Once the plugs have wet out they may spark outside engine correctly but then revert to shorting down the glass under cylinder pressure. You can clean out engine of excess fuel somewhat by whirling it over with starter and throttle wide open and plugs removed then let sit overnight to evap the rest. Carb cleaner will wet the plugs out sometimes, use ether or starting fluid which quickly evaps faster than carb cleaner and it starts better in a situation like that but BE CAREFUL!!!! NO MORE than a 2 second shot in each carb and then block the carb opening by choking it to trap the ether or it quickly evaps out of the carbs. Get ready to start and then quickly pull the chokes open and whirl engine over, if viable it WILL at least pop or run a few milliseconds or something is still wrong with the motor. If it doesn't then DO NOT ADD MORE, you risk an explosion, do NOT underestimate this! I watched a friend blow out 6 of 8 connecting rods in a V-8 engine once abusing the stuff! The stuff is safe as hell when used correctly but it will not tolerate an idiot using it at ALL. Don't take that personal; not intended like that. If the engine runs at all you are likely able to reload it with more ether to go further but NOT until the first load has been burned. Don't be afraid of it, just use it wisely.

Wet plugs must be cleaned and dried. I use alcohol or acetone to degrease them but the tips may need filing at the electrodes to lay bare new sharp metal edges. Spark likes sharp edges to jump off of. May even need brand new plugs if too black.

The valves are fine if it ran before.

If you took the pulser plate loose you have to recertify the airgap there (not to mention the timing too), else the gap wander may weaken the logic pulse that occurs when the reluctor passes pulser and then the pulse is not strong enough to signal a good clean firing point. Or, more weak spark. I tighten up the airgap, closer makes a stronger spark. I use around .012" gap there. The metal parts MUST NOT MAKE PHYSICAL CONTACT.

Check the resistance across the kill switch, more than once too much resistance there has cut spark to not start engines. No number there just as low as you can get it.

Your battery must be known good and hot as in charged 100% or wasting time, if not the starter pulls power off the coils and it never starts.
 
If they run ethanol in your local fuel then it may have clogged the pilots over the storage, I've seen it do it in less than 3 weeks before. The pilots clogged then won't idle (lean) but the clogged idle also makes just off idle (primary jet) go super rich to foul the plugs. The 1-2 whammy these carbs can do to you. It drives guys literally nuts.
 
So this weekend I discovered something strange. I opened left cover over pulse generator to check air gap, and found a gross white oily goo mixture covering everything. Thinking it may have contaminated the metal bars on pulses I cleaned and dried the entire area. Did an oil/ filter change too thinking this may be what the engine oil looks like. Luckily the oil looked ok, but since buying the bike a year ago I haven't changed oil so needed it anyway. Cleaned and dried plugs well and drained gas and put in fresh gas. Started it up today ran on 4 cylinders. Decided to try using choke less and proceeded to start and drive it a few more times today, all on 4 cylinders. Hopefully tomorrow it will do the same. Only things new I did was clean pulse generator and new gas. Maybe one of those was the problem. We'll see.
 
this is what I found under the L side pulse generator cover. A few days I cleaned it and it started easy and ran great. Today started hard again but ran good when it did. Came back and removed the cover to find this again. What is it?
 

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Browsing around I found this thread. The pics show emulsified oil, the question is, where did the water come from? after all the engine is air cooled!
Possibly condensation from not having the engine running or water (rain?) getting past the gasket seal. The oil from a weeping oil seal. Short journeys with long periods not running will cause condensation to form, the short journeys not allowing the water to boil off. It takes about 5 miles or more for the engine to reach full working temperature.
 
Up as far north as you are water can easily condense inside motor parts, but here in the US in many places it is much harder to do that to get actual water in them. Here in Texas virtually impossible. As well, if you run ethanol in the local fuel like so much of the US does then the ethanol will be a far greater problem if any condensation type issue exists because the water aspirated into things by normal day/night temp swings will then collect in the fuel so fast you won't believe it. Here in Texas you will get water now as fast as one minute in fuel exposed to the air where it used to be close to ten, a clear indicator that the ethanol level has gone WAAAY up even thought they claim it hasn't. I never had any trouble at the spec of 10% but now I'm hearing people with % readers saying everything around here is much closer to 20% and illegal, but what to do when it has now become common to break the law outright? Lately I have being seeing issues from it I've never seen before.
 
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